How Long for Tall Fescue Grass to Grow?

Tall fescue quickly creates a soft surface for your next cookout.

Tall fescue (Festuca arundinacea) helps give you a green lawn all year by thriving during the cooler months in U.S. Department of Agriculture plant hardiness zones 3 through 8. It grows quickly, so it requires frequent mowing. It also germinates relatively fast, allowing you to overseed your lawn or seed new areas without having to wait too long to use them.

Seeding Tall Fescue

Tall fescue grows at different rates depending on the temperature. If you seed in the spring when the soil is still cold, the grass might take longer to germinate than in the fall -- it germinates best in soil that's between 50 and 65 degrees Fahrenheit. It grows fastest when air temperatures are 60 to 75 degrees. In the heat of summer, fescue won't grow as quickly as it does when the weather begins to cool in the fall.

Germination

When planted in the fall, tall fescue typically germinates in four to 14 days. Many factors affect the speed of germination, including soil pH, temperature and the watering schedule. Tall fescue grows best in soil with a pH of 5.8 to 6.5, but it can tolerate soil pH levels of 4.7 to 8.5. Water the seeds daily to ensure the soil stays moist to help the seeds germinate quickly.

Mowing

When you see the tiny green sprigs begin to appear, don't grab the lawnmower immediately. Give the seedlings between two and four weeks to grow tall enough to mow without harming them. Waiting until the grass reaches at least 2 1/2 inches tall ensures the roots are established deeply enough to survive mowing. Cut off about 1/3 of the blades' height with each mowing, including the first one. For grass 3 inches tall, for example, remove 1 inch of height. Because tall fescue grows quickly in cooler weather, expect to mow every five to seven days. In the heat of summer, let the tall fescue grow a bit taller -- about 4 inches tall -- between mowings, which you should do less frequently than in the cooler spring and fall.

Left Unchecked

Mowing tall fescue on time is essential for proper management. When left alone, tall fescue can grow up to 48 inches high in a year. This might not be a problem in the center of your lawn that's easy to mow, but if you don't edge or trim other areas, such as around trees or your mailbox, the grass might look out of control quickly. To conserve its health, even tall grass needs only 1/3 of its height cut off at any time; wait three to four days and trim off another 1/3, continuing until the grass is at your desired height.